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Universal Flu Vaccines Promises to Protect Against All Strains

Universal Flu Vaccines Promises to Protect Against All Strains

by Dr. Hena Mariam on Nov 26 2022 3:45 PM
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Highlights:
  • Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs and have the potential to cause pandemics
  • Researchers have formulated a new universal vaccine that can protect against all 20 strains of influenza which could be revolutionary //
  • The vaccine will not prevent people from getting the flu, rather protect against severe illness and death
A newly developed experimental vaccine has generated antibody responses against all 20 known strains of influenza in initial animal tests, giving hope for developing a universal flu vaccine. This could be employed as a preventive measure against future pandemics.
According to the study, the “multivalent” vaccine uses the same messenger ribonucleic acid (mRNA) technology employed in the Pfizer and Moderna SARS-CoV-2 vaccines. This mRNA technology enabled those COVID-19 vaccines (1 Trusted Source
A multivalent nucleoside-modified mRNA vaccine against all known influenza virus subtypes

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).

Tests in animal models showed that the vaccine dramatically reduced signs of illness and protected from death, even when the animals were exposed to flu strains different from those used in making the vaccine.

“The idea here is to have a vaccine that will give people a baseline level of immune memory to diverse flu strains, so that there will be far less disease and death when the next flu pandemic occurs,” say researchers.

Influenza viruses periodically cause pandemics with enormous death tolls. The most commonly known of these was the 1918-19 “Spanish flu” pandemic, which infected about 500 million and killed at least 50 million people worldwide (2 Trusted Source
History of 1918 Flu Pandemic

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).

Flu viruses can circulate in birds, pigs, and other animals, and pandemics can start when one of these strains jumps to humans and acquires mutations that adapt it better for spreading among humans. Current flu vaccines are merely seasonal vaccines that protect against recently circulating strains, but not against new, pandemic strains.

How the Experimental Vaccine Work?

The researcher’s idea behind the vaccine was to vaccinate using immunogens—a type of antigen that stimulates immune responses—from all known influenza subtypes in order to elicit broad protection. The vaccine is not expected to provide immunity that can prevent infections but rather have the vaccine elicit a memory immune response that can be quickly recalled and adapted to new pandemic viral strains, significantly reducing severe illness and death from infections.

Is This Vaccine Similar to COVID-19 Vaccines?

The researchers said that the experimental vaccine would be comparable to first-generation SARS-CoV-2 mRNA vaccines, which were targeted at the original Wuhan strain of the coronavirus. However, against later variants such as Omicron, these original vaccines did not fully block viral infections, but they continued to provide durable protection against severe disease and death.

The vaccine, when injected and taken up by the cells of recipients, starts producing copies of a key flu virus protein, the hemagglutinin protein, for all twenty influenza hemagglutinin subtypes—H1 through H18 for influenza A viruses, and two more for influenza B viruses.

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“For a conventional vaccine, immunizing against all these subtypes would be a major challenge, but with mRNA technology it’s relatively easy,” researchers said.

In mice, the mRNA vaccine elicited high levels of antibodies, which stayed elevated for at least four months, and reacted strongly to all 20 flu subtypes. Moreover, the vaccine seemed relatively unaffected by prior influenza virus exposures, which can affect immune responses to conventional influenza vaccines. The researchers observed that the antibody response in the mice was strong and broad, whether or not the animals had been exposed to flu virus before.

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The research is currently at the stage of designing human clinical trials. The hope is that if those trials are successful, the vaccine may be useful for eliciting long-term immune memory against all influenza subtypes in people of all age groups, including young children and the elderly.

“We think this vaccine could significantly reduce the chances of ever getting a severe flu infection,” researchers said.

Following the same principle, the multivalent mRNA strategy can be used for other viruses with pandemic potential, including coronaviruses.

References:
  1. A multivalent nucleoside-modified mRNA vaccine against all known influenza virus subtypes - (https://www.science.org/doi/10.1126/science.abm0271)
  2. History of 1918 Flu Pandemic - (https://www.cdc.gov/flu/pandemic-resources/1918-commemoration/1918-pandemic-history.htm)


Source-Medindia


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